ΔE 12.8, fair: the same colour family, but not a straight swap. Scarlet Red is noticeably lighter, more saturated than Dirty Red.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Scarlet Red is noticeably lighter, more saturated than Dirty Red.
The same difference applies the other way round: Dirty Red is noticeably darker, more muted.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Dirty Red on the colour wheel See Scarlet Red on the colour wheel
All matches: Dirty Red equivalents · Scarlet Red equivalents